The study on site quality evaluation for dahurian larch (Larix gmelinii Rupr.)

Site quality of larch (Larix gmelinii Rupr.) in Da Xingan Mountain in Inner Mongolia was studied systematically with about 1000 temporary plots and computer software. The nature of site class and site index curve was discussed in view of general mathematical model of height growth. The height growth of dominant tree of four divisions of forest stands were studied and site index tables were constructed respectively. In order to unify the comparing standard and convenience for management in this region, site index table was constucted too. Based on discussing the action and accuracy of forest type, a series of site quality evaluation (forest type-site index class-site index) was suggested. This subject of study is supported by the National Natural Scientific Fund (No. 39270549).     

Site Quality Evaluation for Mixed, Uneven-aged, Natural Forest Dominatedby Korean Pine in Northeast China

1ThisStudyisoneoftheprojectssuportedbyNaturalScienceFundationofHeilongjiangProvinceIntroductionSitoindexisaconvcnientstcptoxtardtl1eultin1ategoaiofpredictingtheproductioncapability'offorcstlwt;anditisausefuldircctmeasuresforapotentialexpetionparadigmintcn…     

安徽亳县泡桐立地质量评定

本文在分析林木直径和树高的相关性的基础上,结合平原农区地形地貌特征,以林分内最大径阶木的平均胸高直径代替优势木的平均树高作因变量,以林分平均林龄和土壤种类、土层厚度、地下水位、株距等定性因子作为自变量,分别编制出安徽省亳县泡桐人工林地位指数表和数量化地位指数表,并在此基础上将泡桐人工林划分为14个立地类型。该项研究对于探讨平原农区主要树种有关经营数表的编制方法、立地类型划分和林木生长预估等具有普遍意义。     

STUDY ON THE SITE OF KOREAN PINE PLANTATION ON THE MAOER MOUNTAIN

1NTRODUCT1oNMaoerMountainliesintheeasternpartofnortheastChinamountainareawithinthenaturalgeographicaldistributionrangeofavaluabletimberspeciesofKoreanpine(PinusKoraiensis).Foraboatmorethanlooyears,cuttinganddestroyingcontinued;f9wnaturalprimaryKoreanpineforestsleft.AlargeareaofKoreanpineplantations,nevertheless,has'grownupastimegoing.Itisapressingproblemforushowtocultivatethemwell,andtorecoveranddevelopthemraPidlyinourforestproductionandscientificresearch.FortheKoreanpinetree,peopledid…     

Growth models and site index table of natural Korean pine forests

IntroductionKoreanpine(PinuskOraiensisSieb.etZucc.)isoneofthemostimportanttimberspeciesanditisnaturaIIydistributedinHeilongjiang,JiIinandLiaon-ingprovincesinChina.ManyforestryresearchersmadeextensiveandprofoundstudiesonthisspeciesJiangYiyin(1985)studiedthegroWthandgrowthmodelsforpIantationsofKoreanpine.However,veryfewpaperswerefoundonthegroWthmodeIsofnaturalKoreanpineforest.Koreanpinehasa1onggroWthperiod.ForextensivelymanagingKoreanpineforest,itneedstheJorestrytabIeswithhighac-Curacy…     

EVALUATION OF SITE QUALITY FOR DAHURIAN LARCH FORESTS

INTRODUCTIONSitequalityisoneofthemostimpor-tantfactorsinfluencingtheproductivityofforeststands.Eva1uatingsitequalityisba-sictostudystandgrowthanddeviseman-agementtreatments.Basisofsitequalityissoil,whichhasacontrollinginfluenceontheforestproductivity-Soilpropertieschangeslowlyovertime,andsoilindexcanbeappliedincutover,deforested,andnonforestedareasinadditiontoareaswheretimberstandsarepresent.Underundisturbed,naturalconditions,somein-dicatorplantscomprisingthelesservegeta-tionmaybeassociat…     

Modelling dominant height growth from national forest inventory individual tree data with short time series and large age errors

We developed dominant height growth models for Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) in Norway using national forest inventory (NFI) data. The data were collected for a different purpose which potentially causes problems for dominant height growth modelling due to short time series and large age errors. We used the generalized algebraic difference approach and fitted 15 different models using nested regression techniques. Despite the potential problems of NFI data the models fitted to these data were unbiased for most of the age and site index range covered by the NFI data when tested against independent data from long-term experiments (LTE). Biased predictions for young stands and better site indices that are better represented in the LTE data, led us to fit models to a combined data set for unbiased predictions across the total data range. The models fitted to the combined data that were unbiased with little residual variation when tested against an independent data set based on stem analysis of 73 sample trees from southeastern Norway. No indications of regional differences in dominant height growth across Norway were detected. We tested whether the better growing conditions during the short time series (22 years) of the NFI data had affected our dominant height growth models relative to long-term growing conditions, but found only minor bias. The combination with LTE data that have been collected during a longer period (91 years) reduced this potential bias. The dominant height growth models presented here can be used as potential height growth models in individual tree-based forest growth models or as site index models.     

I-69杨立地指数表的编制

利用 184个样地的 62 7组数据对 16种生长模型的参数进行了拟合 ,结合 I- 69杨的生物学特性和拟合效果 ,确定利用单分子曲线作为 I- 69杨的立地指数的导向曲线并编制了立地指数表。根据实际情况将立地指数划分为 3个地位级。     

立地管理措施对2代4年生杉木林生长的影响

在福建省南平峡阳国有林场开展5种不同立地管理措施对1片29a生第1代杉木人工林采伐后营造的4a生第2代杉木人工林生产力影响的研究。研究结果表明,5种处理的第2代杉木林地位指数与第1代相比均略有下降。BL3BM0(收获树干和树皮、加倍采伐剩余物)处理的4a生2代杉木林生长最好,地位指数仅比1代下降0．67;其次为BL0BM0(收获地上所有有机质)处理,地位指数比1代下降0．85;BL1BM0(清走树木的所有部分)处理杉木生长最差,地位指数下降1．67。炼山处理(BL2BM1)与保留相同数量采伐剩余物而不炼山的处理(BL2BM0)相比,杉木生长没有显著差异。     

Development of height curves for Japanese larch in relation to GIS-derived site index

The objectives of this study were: (1) to relate the height growth pattern to the GIS-derived site index, (2) to construct various types of polymorphic height curves, and (3) to select the most accurate height curve for Japanese larch (Larix kaempferi). A total of 14 dominant trees were felled for stem analysis. Richards' function was first fitted to the height/age dataset recorded from stem analyses of 14 trees, and its parameters (i.e., A, k, and m) were then estimated for each sample tree. The relationship between parameter A and the GIS-derived site index was significant, while that of parameters k and m were not significant. The 12 height curve equation forms developed from the Richards' function were then fitted to the dataset consisting of 563 observations of height, age, and GIS-derived site index derived from 14 trees. All height curves were unbiased and provided an equally good fit. The shape of the height curves differed among sites of different site indices. These results indicated that Richards' function was sufficiently flexible to represent the polymorphic height growth pattern of Japanese larch. Finally, the best-fit height curve was selected so that accurate height growth predictions would be possible at any given age and site.     

Site index models for Calabrian pine in the central Mediterranean region of Turkey

Stem analysis data of 432 trees were obtained from even-aged, pure natural stands of Calabrian pine in the central Mediterranean Region of Turkey. Eight dynamic site equations derived with the Generalized Algebraic Difference Approach (GADA) were compared, based on autoregressive analysis and a thorough evaluation of the goodness of fit. We used generalized nonlinear least squares methods for model fitting. The adjusted coefficients of determination (0.9825–0.9842), root-mean-square errors (0.8004–0.8435 m), and Akaike’s information criterion differences (0–145) indicated a good fit of the eight site index equations. The Hossfeld equation (M3) provided the best result. The Durbin-Watson test statistic did not reveal an autocorrelation issue while the Hossfeld equation provided a satisfactory solution to the serial correlation problem in stem analysis data as time series using autoregressive modeling. This study presents new site index models for Calabrian pine forests in the central Mediterranean region of Turkey where it is the most important commercial tree species. The site index equation, based on the Hossfeld model is recommended for height growth prediction and site classification of Calabrian pine stands in the central Mediterranean region of Turkey, providing a new basis for growth prediction and yield estimation in these important forest ecosystems.     

马尾松天然次生林间伐效应研究

于平均年龄为23年生、地位指数为14和12的2种立地的马尾松天然次生林中,分别设置固定标准样地,并分别设计5个和6个密度水平,对其抚育间伐4年后的间伐效应进行研究。结果表明:不同地位指数的林分,其间伐前或间伐后立木径级分布均呈现正态分布的规律;间伐前林分分化强烈,立木径级大小悬殊;间伐后林分最小株距和平均株距较接近,大径级林木比例提高;间伐4年后平均径级左右的立木比例明显增加。间伐4年后,当14地位指数林分的密度大于1 500株/hm2,12地位指数林分的密度大于1 950株/hm2时,其胸径离散度较间伐当年间伐后的反而明显增大;平均胸径和单株材积的增长均随保留密度的加大而减小,但单位面积蓄积量增长则在其适宜密度时最大;不同保留密度各处理间平均胸径、单株材积以及单位面积材积增长的差异均达极显著,但树高和比重增长的差异均不显著;间伐各处理的平均胸径、单株材积以及单位面积材积增长均大于对照;14地位指数马尾松林以保留密度为1 500/hm2处理的单位面积材积增长最大,增长30.29%;12地位指数马尾松林以保留密度为1 950/hm2处理的单位面积材积增长最大,增长24.38%。     

立地条件对落叶松人工林生长的影响

通过对日本落叶松(Larix kaempferi)人工林在不同立地条件下的生长调查,结果表明,日本落叶松在生长过程中,受土层厚度、林地位置、立地指数等多方面因素的制约:厚层土胸径年生长量比中层土和薄层土高9.2%～26.7%,树高年生长量高21.8%～44%;生长在N坡,坡度较缓、山地下腹为优;在不同的立地指数级中,生长差异明显,18以上指数级比14～18指数级胸径生长量高25.4%,比14以下指数级胸径生长量高33.8%,树高生长量,18以上指数级比14～18指数级高26.7%,比14以下指数级高36.3%。培育日本落叶松人工林,选择优质立地条件不但可提高林木的生长速度,又能促使林木优质高产。     

遂宁地区香椿人工林数量化立地指数的编制及应用

通过对遂宁地区香椿(Toona sinensis Roem)人工林标准地的调查,分析各标准地优势木平均树高与立地条件(土壤质地、地下水位、排水状况、夹层、p H值、土壤母质、紧实度等因子)之间的关系,最终编制出以土壤质地、地下水位、排水状况、夹层4因子为主的数量化立地指数表,对遂宁浅丘农区相似区域香椿造林经营具有一定的指导意义。     

基于多形曲线法的林分地位指数研究

以生长于一平浪林场的云南松林为研究对象,利用该林分小班的二类调查数据进行了单形树高生长导向曲线,多形树高生长导向曲线构建并编制地位指数表的研究。结果表明,运用多形曲线法,假设不同立地条件下的树高生长曲线不相同,利用不同形状不同发展趋势的多形曲线来描述各立地条件下的林分生长状态,它能够解决单形曲线法在样地的树龄、立地分布不均时,导致的导向曲线的斜率偏高或偏低的现象。由此表明,建立多形导向曲线法编制地位指数表很有价值。     

Site quality of pedunculate oak (<Emphasis Type="Italic">Quercus robur</Emphasis> L.) stands in Galicia (northwest Spain)

Accurate estimates of forest productivity are required for sustainable forest management. Height of dominant and codominant trees at a reference age is often used as a measure of site productivity. Eight algebraic difference equations based on the models proposed by Sloboda, Bertalanffy-Richards, Korf, Hossfeld, and McDill-Amateis were tested on the transformed, longitudinal data structure that considers all possible growth intervals. Autocorrelation was modelled by expanding the error term as an autoregressive process according to this data structure. Generalized nonlinear least squares methods were used for model fitting. Several numerical and graphic analyses were used to compare the different candidate models. The relative error in dominant height prediction was used to select 60 years as the best reference age. An algebraic difference equation based on the model proposed by Korf provided the best compromise between biological and statistical aspects and produced the most adequate site index curves. This model is therefore recommended for height growth prediction and site classification of pedunculate oak stands in Galicia. The model is polymorphic and base-age invariant, having only one asymptote. Predictions of height for age intervals between t₁ and t₂ of more than 15 years should be considered with caution because of the associated critical error.     

杉木人工林地位指数表简捷编制方法研究

利用浙江省开化林场杉木人工林36块标准地和144株解析木资料,比较分析5个树高生长模型后,选择Krof式生长函数H=aexp(-b/Ac)作为优势高生长模型。在分析优势高生长过程的基础上,确定基准年龄为20a,立地指数级距为2m。通过公式变形和推导,使用较简捷的方法编制了浙江省开化林场杉木人工林立地指数表。检验结果表明所编立地指数表精度符合要求。     

基准年龄立地质量评价的影响分析

Taking Chinese fir as researched object and Richards function as basic model,the models of single site index and polymorphic site index were established to analyze the affect of stand standard age on the result of site quality evaluation with the ways of ANOVA, multicompare,curve tourning point and change of dominant tree height between site classes. The result showed that with the site class getting higher,curve tourning point volue getting lower,it was impossible to define the standard age before stand growth reached steady. If stand standard age is too small, it would lead to a higher site calss in polymorphic site index evaluation; The difference was notable among stand dominant height from difference standard age,if standard age is too small, it would lead to a lower site class in single site index evalution. Taking the age steady-grown stand as standard age would not make notable affect on the result of site quality evaluation.     

柏木人工林立地质量与林分结构规律的研究

本文通过对柏木人工林林分结构时、空间变化规律的研究,发现林木株数按径级的分布在幼龄期呈倒“丁”型,在中龄前期低指数级呈倒“丁”型,高指数级近似正态分布,而中龄后期为近似正态和正态型,随年龄和指数级的增大其径级分布从倒“丁”型向正态分布里有序的过渡;分析了不同立地质量下林分(?)、(?)、(?)及生物量等生长指标的变化规律,并建立了指数级和各指标之间的函数回归式,以实现对不同立地质量林分的评价预测;分析探讨了不同经营目的下林分的合理密度,为柏木人工林经营提供了技术指标和依据。     

马尾松天然林立地质量评价

利用二类调查固定样地资料 ,分析了马尾松天然林上层木平均高、胸径与年龄三者之间的关系。结果表明 :年龄在决定马尾松天然林上层木平均高时意义不大 ,而上层木平均高与胸径的相关性密切 ,符合Richards方程。故采用上层木在一定胸径 ( 35cm)时的高度值表示立地指数。讨论了这种评价方法的理论基础、精度及其天然异龄林经营实践中的意义